The present invention relates to communications networks and particularly to the management thereof.
Competitive advantage can be gained by communications network operators through the services that they offer and the efficiency with which they manage those services. Targets that a network operator might aim for include reduced charges, improved quality and increased customer control of services. Part of the networking infrastructure that might facilitate these customer offerings may well be the Global Multi-Service Networks (GMSNs) which enable network operators to offer their customers:
Rapid service provisioning
Controlled quality of service
Integrated services
Regulated control of network services
Ideally, these facilities will be offered with the same availability as voice connectivity is today but providing many new features together with mobility and movability of customers.
To enable network operators to offer their customers the extensive flexibility, quality and control the above demands, GMSNs will need to support:
Multi service provision
Multiple vendors
Multiple administrators
Flexible service management
The complexity and operational characteristics of GMSNs are expected to impose requirements beyond the capabilities of current network management approaches. Not only will the GMSNs have to provide services to the customer according to contract but price and performance will have to be optimized at the same time For the network operator.
A Multi-Service Network (MSN) is any network that is capable of supporting a range of services. The Pan-European Integrated Broadband Network investigated in a European PACE initiative, and referred to in the paper xe2x80x9cBroadband Communication Managementxe2x80x94The RACE TMN Approachxe2x80x9d presented by R Smith at the IEE Broadband Conference in London in 1990, an example of a MSN based on the Asynchronous Transfer Mode. There are networks currently available in the USA which are examples of MSNs that use more conventional switches (e.g. DMS 250 from Northern Telecom). Such networks can be used to transmit voice as well as data. The data can be split into various transmission rates, for instance from 19 kbits/sec up to 40 Mbits/sec, so that a range of services from file transfer to real time video can be supported. Furthermore, the trend in such networks is towards global networks where the MSN can span many countries, hence the emergence of GMSNs.
Initially at least, the intended customers for MSNs are expected to be large corporate users, perhaps with many sites situated world-wide. Such a customer will require a network which appears to be a private switched network, providing at least the functionality that they enjoy from the international private leased circuits. In fact the service can be supported by a number of underlying networks, possibly from many different network operators. This arrangement is known as a virtual network.
Service Level Agreement (SLAs)
These companies often entrust a large proportion of their world telecommunications requirements to one service provider by contract. It is extremely important that they are provided with the level of service specified in their contract. The exact definition of the service is specified in a Service Level Agreement (SLA). The range of services available is potentially extremely large, and each service can be further customised since each service has a range of options. Example services include:
Dedicated international private eased circuits
Routing controlled by
time of day
calling identity
originated location
Customer controlled dialing plans
An example of the latter is where a user needs only to dial 111 to get through to the relevant sales department, regardless of where the call is originated geographically in relation to the sales department.
A SLA can be expected in general to include:
Grade of Service (blocking probabilities, bit error rate, error free seconds etc.)
Target and guaranteed minimum provision times
Target and guaranteed minimum cessation time
Target and guaranteed minimum repair times
Target and guaranteed service availability
Working in object oriented software technology, models for services and SLAs have been developed by the International Standards bodies (OSI/NMF and CCITT). These provide Generic Managed Object classes that define services and SLAs. The concept of a feature Managed Object is introduced to define a component of a service that can be offered to the customer. The logical numbering scheme permitted in Intelligent Networks is an example of such a feature. Features can be xe2x80x9cnestedxe2x80x9d so that one feature is a component of another feature. The mapping from the feature to the underlying network resources is also defined in the feature object. In an intelligent network of known type, having a structure including a service control point (SCP) (or other means) for making reference to service and/or customer data, the service control point (SCP) would typically be a resource or, which many features (i.e. logical numbering, time-of-day routing) depend.
Information about billing, fault handling and performance criteria may also be held within a feature, so long as it is common to all instances of that feature. It is possible for instance though that the performance criteria of some features will depend or, the use to which they are put.
A SLA is then defined in terms of the component features that support the service in question. In addition to this, information about the contract and a description of the service covered by the SLA is also kept. A SLA will typically refer to a number of features, which in turn may refer to other features and resources. To support this relationship a number of dependency relationship types can be defined (supports, depends-on etc).
Multi Service Network Management
The customer is also likely to require the ability to manage their own virtual network: services can be requested, altered and ceased by the customer from on-line connections to the service provider""s equipment.
All this complexity makes network management an extremely difficult matter, particularly where reconfiguration is required, and particularly in the light of SLAs.
Providing Multi-Service capabilities across more than one country is likely to require considerable capital outlay. To make such a network viable the operating cost has to be kept within tight constraints. To meet this operating cost constraint, extensive automation of management functions in the network will be very attractive, if not essential.
According to embodiments of the present invention, this automation will be achieved at least in part through the use of Cooperating Intelligent Software Agent technology. The basis for such technology is described in general terms in various publications including:
i) xe2x80x9cDistributed Artificial Intelligencexe2x80x9d by M Huhns, Volumes I and II, published by Pitman, Morgan, Kaufmann in 1987;
ii) xe2x80x9cFundamentals of Distributed Artificial Intelligencexe2x80x9d by D G Griffiths and B K Purohit, published in British Telecommunications Technology Journal, Volume 9 No. 3, in July 1991; and
iii) xe2x80x9cThe Role of Intelligent Software Agents in Integrated Communications Managementxe2x80x9d by D G Griffiths and C Whitney, in the same issue of the British Telecommunications Technology Journal.
The relevant content of each of the above is herein incorporated by reference.
Particular aspects of network management which might be automated by means of embodiments of the present invention, together or separately, include the establishment and restoration of routes in an underlying physical network while maintaining customer requirements satisfaction.
Long Term Service Provisioning
Service provisioning is a requirement of any telecommunications operator. Service provisioning for a GMSN tends to differ from conventional networks because of the following characteristics:
A large range of services
A wide range of customer types
Complex SLAs with financial penalties
Network(s) spanning more than one country
It is likely to be a requirement that when a customer requests that a new service be provided, they should receive a quote and an indication of timescales within a fixed time. The customer ruts in a request for a new service (possibly via a management terminal for existing customers, or through a negotiator For new customers) and will expect to be told how much the service is acing to cost and when it can be made available. If the service cannot be supported by the existing network configuration then some reconfiguration is clearly required and many well involve the provisioning of new equipment.
Real-time Network Reconfiguration
When a network element fails, a number of services could be affected. They could fail completely or they could fail partially but their quality of service may drop below that defined in the customer SLA. When such faults occur, alternative ways (through network reconfiguration) must he found for re-establishing the same service.
In a conventional network (e.g. as provided to date in the UK PSTN) such reconfiguration is controlled by routing tables in the switch (e.g. System-X exchanges). The switch automatically attempts to re-route around problems in the network through control actions from a central operations unit. This routing takes no direct account of the type of traffic that is being routed and, as a result, all traffic is treated equally.
In a more complex network (such as GMSNs), where there is a wide range of services and a large number of different customer types, this simple approach is not so viable. It is no longer safe to assume that all network usage is of equal importance.
According to the present invention, were is provided a communications network management system comprising a distributed control system based on cooperating intelligent software agents, wherein reconfiguration of either the communications network or of the agents can be carried out under the control of the agents.
Such reconfiguration would be triggered, for instance, by a request from a customer for a new service, or in the event of agent failure.
In the case of agent failure, in particular, it may be very important that the reconfiguration be carried out very fast so as to maintain or reestablish services. It will also be important that the control systems refer to SLAs to see which services have priority in the face of pending or actual failure. Thus when a network fault occurs all (or all significant) affected services need to be detected and the consequence these have on agreed SLAs investigated. The broken SLAs will be ranked in order of urgency and the network preconfigured to restore service in such a way that minimizes the consequences of the failure.
An embodiment of the present invention can be described as an open heterogeneous system architecture based on autonomous software agents working cooperatively to solve a sub-set of service management problems in a GMSN. The service management problems concerned might include the above mentioned real-time reconfiguration together with service provision in response to customer request.